Rheostat fixture for electric lights



June 1929- c. L. WEICHELT ET AL RHEOSTAT FIXTURE FOR ELECTRIC LIGHTS Filed Nov. 12, 1926 .1 cano or enclosin element.

Patented June 4, 1929.

UNITED STATES PATENT OFFICE.

TION OI MAINE.

RHEOSTAT FIXTURE FOR ELECTRIC LIGHTS.

Application filed November 12, 1926'. Serial No. 147,965.

This invention relates to the class of attachments of incandescent electric lights employed for regulating the amount of current delivered from a current source generally designated as the main wires.

Our invention comprehends briefly a stationary rheostat and a rotatable contactor, the former being mounted on and the latter recessed in a base of insulating material, provision being made to limit the oscillatory movement of the contactor.

The invention also has for its object to provide an improved lamp fixture embodying the features of adjustability of intensity of illumination of the lamp in which certain improvements in the arrangement of the parts facilitates the operation of making the wiring connections, mounting the elements upon the usual outlet box and finally mounting the To these ends we have provided a special form of adjustable mounting bracket and made provision for separately securing thereon the lamp supporting unit and the canopy. Still another feature of our invention is the utilization of the end of the stationary rheostat projecting beyond the canopy-as a support for the lamp shade.

To these and other ends our invention consists in further improvements and detail arrangements of elements all as will be further described in the specification and particularly set forth in the appended claims.

The invention is illustrated in the accompanying drawings which show the present commercial form of the lamp fixture. In these illustrations,

.Fig. 1 is a side view of the assembled device, the canopy being shown in section.

Fig. 2 is a horizontal cross-sectional view taken on the line 22 of Fig. 1.

Fig. 3 is an end view of the parts as assembled in Fig. 2.

Fig. 4 is abottom view of the rheostat shell removed from its insulating support.

Fig. 5 is a plan view of the insulating suport. p Figs. 6 and 7 are views of the front and rear faces of the rotatable brush carrying member or contactor.

Fig. .8 is a perspective view of the adjustable connector for attachment to the outlet box.

In the several figures, similar characters indicate similar parts,

In carrying out our invention, we have provlded a lamp support comprising the standard screw socket arranged within a rheostat which projects beyond the canopy and is carried on a base of insulating material. The latter is supported independently of the canopy by being aflixed to a special adjustable support provided for attachment to theusual outlet box and which forms the subject matter of our copending application, Serial No. 147,964, filed concurrently herewith. The design of these parts is such that the insulating base with the lamp carrying parts may be rigidly mounted in position, the

wiring connections completed, the canopy applied and secured directly to the outlet box attachment and the lamp shade placed in position and firml secured. In illustrating e invention, the fixture is shown as comprising a tubular rheostat mounted on a base 1 and formed of outer and inner concentric shells 2 and 3, between which is located a resistance element 16 comprising a plurality of coils of wires with alternate wrappings or layers of sheet insulating material embedded in a baked and hardened bed of insulating material, as indicated. This element with the invention set forth more in detail in the pending application of Carl L. Weichelt, Serial No. 98,171, filed March 29th, 1926. .The base 1 is ,a cylindrical porcelain block having plane surfaces 4 and 5 (see Fig. 5) at its top and bottom edges, intermediate inclined faces 6 and 7 and a central recess 80 accommodating the rotor or connector which cooperates with the terminals of the rheostat windings. The rheostat shell 2 has laterally extending flanges 4 and 5 fitting the faces 4 and 5 of the base, these parts being each provided with. two sets of perforations 8, 8 and 9, 9 to accommodate the pairs of binding screws8", 9 which serve respectively to mount the rheostat and base 1 on the terminal box connector and the canopy 10 to said connector. Within each of the faces 6 and 7 recesses are provided to accommodate the line'wire terminals 6, 7 a which are rigidly secured by screwsll, as shown in Fig. 2. Each, of these terminals is preferably inclined to receive the downwardly and outis preferably made in accordance wardly projectingterminals 12 and 13 connected to the extremities of the rheostat-memher one being connected to the inner shell 3 and the other to one end of the rheostat coil. Binding screws 6", 7" are provided for con- .necting these terminals to the terminals 6,

7- and also for connecting the line wires 14 and 15'to them; thus it will be seen that the rheostat is connected to the base 1 in the process of assembly independently of the fastening screws 8 8 The inner shell 3 of the rheostat is provided at opposite sides with inturned flanges against which rests the correspondingly slotted bottom of the screw threaded lamp socket 20 which is secured in this position by tubular rivets 21 which pass through the bottom flanges of shell 3 and through a circular insulating block 22. A center-shoulder on the latter projects into the socket and is provided with a longitudinal depressionin which the spring center lampcontact member 23 is seated and held in position by a stud 24 on which the contactor shown in Figs. 6 and 7 is rotatably mounted in rear of the rheostat.

The resistance element of the rheostat is tapped to contacts 25, 26,27 and 28 (Fig. 4) having their extremities exposed in the plane of the flanges 4 5 and cooperating therewith is a brush or wiper'29 in the form of a spring finger on a circular plate 30 secured to a disc 31, of. insulating material, by a collar 32,'in the form of a tubular rivet passing through said disc. In order to balance the latter it has been found desirable to make the plate .30 with a diametrically located spring finger 29, which bearing lightly against the smooth surface of the insulated portion of the end of the rheostat obviates any tendency of the disc to wabble on its hearing. In order to provide for convenience in assembly, smooth operation of the brush and also for satisfactory electrical contact in the bearing, the latter is made somewhat larger than the stud 24, the intervening space being taken up with a bushing 32 which is so iiciently long to enter a central recess in the block v22 and contacting with the bottom thereof to form a spacer so that the stud may be drawn down tightly by the nut 33 Without interfering with the free rotation of the adjustable element.

When no contact is established between the i brush 29 and the resistance contacts, the circuit is incomplete and no current flows through the device. The circuit is completed by rotating the contactor until the brush makes electrical contact with one of the resistance contact-s aforementioned, in which event the circuit may be traced as follows:

from the base terminal '7", to the rheostat terminal 13, through all or a portion of the resistance 16, to one of the contacts 25, 26, 27 or 28, brush 29, stud 24, spring finger 23,

the lamp center terminal, through the lamp filament to threaded metal lamp shell 20, inner rheostat shell 3, terminal 12, and base terminal 6'.

Oscillatory movement of the brush 29 is accomplished by pulling upon either of the free ends 34 or 35 of a chain or cord attached to the disc 31.- The latter is provided with an annular channel 40 to accommodate a ball chain, the inner ends of which are attached to a yoke 41. Stepped within the channel 40 is a second arcuate recess 42 the extremities of which form stops that cooperate with a projection 43 extending within the recess 80 in the base 1 to limit the rotation of the brush in opposite directions.

At one side of the base 1 slots 43 lead outwardly from its central recess to accommodate the ends of the-pull chains and as the flange 5 overlies these there is attached to the underside of this flange an arcuate shaped piece of insulation 44 which prevents the possibility of contact between the chains and the rheostat shell.

In F ig. 8 there is illustrated an improved site corners, inturned ears carrying screws by means of which auxiliary devices may be attached. Inasmuch as it is impossible for the fixture manufacturer to know in advance the type of outlet box which the installer of the wiring system may use it is desirable to pro;

vide a form of connection thatis universally-f adjustable. Another and equally important reason for using such 'a connection arises from the fact that it is not always posisble for the installer to place an outlet box so that'the attachment screws will occupy an intended position with reference to horizontal and ver...

tical planes; hence it becomes essential that;

provision be made whereby the fixture when it is applied may be adjusted to any required or desired position irrespective of the fixed position of the outlet box. In the type of connection shown in Fig. 8, these results are accomplished by providing a securing member in the form of across-arm 46 having ofi'set slotted ends to receive the attaching screws in the outlet box. Extending in rear of this arm is' a fixture mounting plate 47 having a central hub 48 extending into an aperture in said plate and upon which the plate and cross-arm may be rotated with respect to each other. Surrounding the hub, the cross-arm is provided with circular edges 48 and cooperating therewith are the overlying edges of the heads of binding screws 49. At the ends of the plate 47 are brackets comprising the forwardly extending portions 47*. and the inwardly bentends 47", the dimensions of which may be vawith our invention ried in accordance with the type of fixture to be supported. In the. instant case, the portions 47' are provided with two threaded apertures to receive the two sets of mounting screws 8 and 9 The canopy 10 shown in Fig. 1 may be made of porcelain and of any desired configuration. Its base is of a diameterto cover the outlet box 45 and its height is arranged to cooperate with the rheostat to enable the latter to be used as a support for a shade 50. To this end the outer shell 2 is provided with a screvg thread and fitted with a thin metal nut 51 which-engages within the neck 52 of said shade and serves to hold it in engagement with the outer edge of the canopy.

A lamp fixture constructed in accordance possesses the advantage of being compact and the rheostat being rigidly connected to the base which is permanently fixed in position securely holds the lamp and also provides a means for holding the lamp shade. Further the arrangement of the parts is such that their assembl in the first instance may be done quickly an accurately and the wiringconnections may be subsequently completed without the possibility of deranging the parts.

We claim as our invention:

1. In a lamp fixture, the combination with a tubular rheostat comprising a resistance having a plurality of contacts, a lamp socket shell within the rheostat, an insulated center contact insaid shell and an oscillatory switch member making direct electrical circuit with said center contact and cooperating with the resistance contacts, of a base of insulating material secured to the rheostat having a recess accommodating the switch member and provided with a lateral opening and means for operating said switch extending througl-i said opening.

2. In a lamp fixture, the combination with a tubular rheostat comprising a resistance having a plurality of contacts, a lamp socket shell within the-rheostat, an insulated center contact in said shell, a shaft extending therefrom, a rotatable insulating member carried by and journaled on the shaft and a switching wiper on said member cooperatin with the contacts in circuit with the sha said shaft providing electrical connection between said center contact and said wiper, of a base supporting the rheostat and enclosing the switching member and having apertures extending laterally in alinement with the sides of the rotatable member and flexible means extending through the apertures and engaging a rotatable insulatin member.

3. In a device of the c aracter described, the combination with a base, a stationary rheostat mounted thereon comprising a resistance having aplurality of contacts, and a shaft carrying a center lamp contact, of a rotatable wiper mounted on a circular body -a center shaft rigidly held from said means and projecting into the base recessand a 1'0- tatable switch member journalled on and in electrical connection with said shaft and cooperating with the resistance contacts, and means for rotating the member.

5. In a lamp fixture, the combination with a base having a central recess, a tubular member having an outer shell provided with securing flanges extending laterally on the base and comprising a resistance having terminals and means within said member for supporting the base of an electric lamp, of a center shaftvsecured to and extending from said means into the base recess, a contactor rotatably mounted on and in electrical connection with said shaft and cooperating with the resistance terminals, means for securing the rheostat and base together and means extending outside of the base for operating the contactor.

6. In a lamp fixture, the combination with a support, a base thereon, a tubular rheostat member comprising an outer shell and an inner lamp socket shell and a resistance element having contacts, said outer shell having flanges restin on the base and said support, base and rieostat being secured .together by means of bolts passing through said flanges, of a switch within the base adapted to engage said resistance contacts, an insulated center lamp contact within the socket shell and means extending there rom securely holding the lamp contact and carrying the switch in operative position.

7. In a device of the the combination with a base having a central recess and carrying terminal members for connections to line wires, a tubular rheostat member secured to said base and comprising a resistance element having a plurality of contacts, a lamp socket shell within the rheostat, an insulated lamp center contact in said shell and an oscillatory switch member within said base recess and cooperating with the resistance contacts, of conducting elements joining the shell and the resistance to said terminal members on the base and a conducting bolt holding said center contact and extending through said switch member to provide rotation of the character described,

latter around it and to establish, electrical connection between the center contact and the member.

8. In alamp fixture, a lamp socket, .a tubular rheostat surrounding it comprising a resistance having a plurality of intermediate contacts, conducting elements extending outwardly from the rheostat and connected to the lamp socket and to the resistance, a rotatable switeh'member cooperating with the resistance contacts, a base of insulating material fitting against the bottom of the rheostat, and haying a recess accommodating the switch'member and carrying wiring connections for attachment to said conducting elements and to line wires, and a canopy enclosing said parts having an outer end embracing the rheostat adjacent the base.

. 9. In a lamp fixture, a lamp socket shell,

a tubular rheostat surrounding it comprising an outer shell having flanges and a rheostat element having a plurality of contacts, conducting elements extending outwardly from the rheostat and connected to the lamp socket and to the resistance, a rotatable switch member cooperating withthe resistance contacts, a base of insulating material fitting against the outer shell flanges, said base having a recess accommodating the switch member and carrying wiring connections for attaching to said conducting elements and to line wires,

L said conducting elements also serving as an attachment of said rheostatto said base, and a canopy enclosing said parts having an outer end embracing the rheostat adjacent the flanges.

10. In a lamp fixture, a support serving as an outlet box connector, a circular base there on having a central recess and a plurality of sets of perforations in its edges, a rheostat of lesser diameter than the base comprising an outer shell having laterally extending perforated flanges fitting against the base and comprising a resistance winding having contacts and an interior lamp socket shell, a switch member located in the recess of the base and cooperating with said contacts, conducting elements extending outwardly from the rheostat and connected to the lamp socket and to the resistance, said base carryln wiring connections for attachment to sai conducting elements and to line wires, said conducting elements also serving as an attachment of said rheostat to said base, a canopy enclosing said parts having anouter end embracing the rheostat adjacent said flanges, se-

ing laterally extending flanges fitting against the base and comprising an inner resistance winding provided with contacts and an interior lamp socket shell, a switch located in the base recess and cooperating with the contacts, conducting elements extending outwardly from the rheostat and connected to the lamp socket and to the resistance, said base carrying wiring connections for attachment to said conducting elements and to line wires, acanopy enclosing-said parts having an outer-end embracing the rheostat adjacent said rheostat flanges, means to secure the canopy, the rheostat flanges, the base and the support together, a lamp shade having a neck surrounding the projecting end of the rheostat and resting aga'instthe canopy and a nut threaded on the rheostat and engaging within the neck of the shade.

. CARL L. WEICHELT.

HARRY F. GILL. 

